Various medical instruments may be used in connection with an endoscope for performing a number of operations at a site deep within a patient's body cavity. One such instrument, a biopsy forceps device, samples tissue from a body cavity with minimal intervention and discomfort to patients. Typically, a biopsy forceps device, like other endoscopic instruments, has a long flexible tubular member for insertion into a lumen of an endoscope. The tubular member is sufficiently long and flexible to follow a long, winding path of the body cavity. An end effector assembly, such as a biopsy forceps assembly, is attached at a distal end of the tubular member, and a handle is attached at a proximal end of the tubular member. The handle may have an elongate portion and a spool portion disposed around the elongate portion. The spool portion may be configured to move longitudinally relative to the elongate portion. An elongate mechanism, such as pull wires, extend through the tubular member to connect the end effector assembly to a hypotube. The hypotube is then connected to a portion of the handle, such as the spool portion. Longitudinal movement of the spool portion relative to the elongate portion of the handle causes the elongate mechanism to move longitudinally in the tubular member, which in turn causes the actuation of the end effector assembly.
In methods of using the biopsy forceps device, an endoscope is placed in a patient's body cavity adjacent to a tissue site from which the acquisition of a tissue sample is desired. The biopsy forceps device is then advanced to the tissue site via a working channel of the endoscope. Once the biopsy forceps device is next to the portion of the tissue from which the acquisition of a tissue sample is desired, the spool portion is moved relative to the elongate portion so as to move the hypotube and the pull wires. The movement of the hypotube and the pull wires causes the jaws of the biopsy forceps assembly to open. The open jaws are then advanced to the tissue site, and the spool portion is again moved relative to the elongate portion so as to move the hypotube and the pull wires such that the jaws close. The closing of the jaws causes a tissue sample to be lodged in the end effector assembly. The biopsy forceps device is then removed from the body cavity via the working channel of the endoscope.
During various endoscopic procedures, including biopsy procedures, the body cavity, such as the colon, may be insufflated to, for example, widen the organ so that the physician has a better view of the tissue site and/or the body cavity. Insufflation may be accomplished by forcing air into the body cavity, for example, before, during, or after advancing the biopsy forceps device into the endoscope and into the body cavity.
An endoscope typically includes appropriate seals to prevent the escape of the insufflated air out of the body cavity and to the external environment via the endoscope. In some cases, however, some of the air forced into the body cavity during insufflation escapes into the outside environment via the end effector assembly, the lumen of the elongate shaft member, and the handle assembly. This escape of air hinders the insufflation and the maintenance of the internal organ pressure. In addition, it can result in undesirable spraying of air or other gas or liquid into the operating room and onto those performing the procedure.